FRIDAY, Dec. 9, 2016 (HealthDay News) -- Insomnia is common in adults with asthma and tied to worse asthma control and other health problems, a new study finds.

University of Pittsburgh researchers found that 37 percent of adults with asthma also had significant insomnia. Those with insomnia had worse lung function. They also weighed more. And they tended to have lower incomes than those without insomnia, the study found.

Insomnia was also linked to a reduced asthma-specific quality of life. People with asthma and trouble sleeping had more depression and anxiety symptoms, the study found. They also needed more asthma-related health care in the past year.

The study was published in the journal Chest.

Although the study wasn't designed to prove a cause-and-effect relationship, the researchers suggested that their findings show that insomnia affects people with asthma. They also said that evaluation and treatment of insomnia should be considered for people with asthma.

"Our results show that poor sleep may not be solely due to nighttime awakenings due to asthma symptoms but may represent comorbid insomnia," study lead author Faith Luyster said in a journal news release. She is an assistant professor in the university's School of Nursing.

Comorbid insomnia refers to sleep troubles that occur at the same time as asthma, but aren't caused by the asthma. Luyster said co-occurring insomnia appears to significantly affect asthma outcomes, such as quality of life and the need for health care.

The study authors said additional research is needed to learn more about the association between insomnia and asthma control.